When we discuss web site design, we should really be saying aesthetics, because that is what most people are really referring to in that aspect. Design really does encompass a few more things though, none anywhere near important as usability.
Usability is simply defined as the ease of use for something. Many people find the usability of Macs superior to PCs. This same function applies to web sites.
Take the example of the most usability friendly website in the world, Google.com. The purpose of that web site is to allow people to search for information and that functionality is prominently featured, very similarly to the way you should present your website.
Now don’t get me wrong, I’m not suggesting that all your company’s information should be on your home page. It should however be easily accessible via the home page along with all the other primary functionality of your web site. What you are aiming for is a graphical interface that your potential and current customer can use with out saying “What does that do,” “Should I click that,” or “How does this work?” If you can do that, then you’ve nailed usability.
